ACC/AHA/NASPE 2002 guideline update for implantation of cardiac pacemakers and antiarrhythmia devices: summary article: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (ACC/AHA/NASPE Committee to Update the 1998 Pacemaker Guidelines)

Pre-op considerations in neuromuscular scoliosis deformity surgery: proceedings of the half day course at the 58th annual meeting of the Scoliosis Research Society

Scoliosis is a common complication of neuromuscular disorders. These patients are frequently recalcitrant to nonoperative treatment. When treated surgically, they have the highest risk of complications of all forms of scoliosis. While recent studies have shown an improvement in the rate of complications, they still remain high ranging from 6.3 to 75% depending upon the underlying etiology and the treatment center (Mohamad et al. in J Pediatr Orthop 27:392-397, 2007; McElroy et al. in Spine, 2012; Toll et al. in J Neurosurg Pediatr 22:207-213, 2018; Cognetti et al. in Neurosurg Focus 43:E10, 2017). For those patients who are able to recover from the perioperative period without major complications, several recent studies have shown decreased long-term mortality and improved health-related quality of life in neuromuscular patients who have undergone spine fusion (Bohtz et al. in J Pediatr Orthop 31:668-673, 2011; Ahonen et al. in Neurology 101:e1787-e1792, 2023; Jain et al. in JBJS 98:1821-1828, 2016). It is critically important to optimize patients preoperatively to minimize the risk of post-operative complications and maximize long-term outcomes. In order to do so, one must familiarize themselves with the common complications and their treatment. The most common complications are pulmonary in nature. With reported rates as high as 23-29%, pre-operative optimization should be employed for these patients to minimize the risk of post-operative complications (Sharma et al. in Eur Spine J 22:1230-1249, 2013; Rumalla et al. in J Neurosurg Spine 25:500-508, 2016). The next most common cause of complications are implant related, with 13-23% of patients experiencing an implant-related complication that may require a second procedure (Toll et al. in J Neurosurg Pediatr 22:207-213, 2018; Sharma et al. in Eur Spine J 22:1230-1249, 2013) Therefore optimization of bone quality prior to surgical intervention is important to help minimize the risk of instrumentation failure. Optimization of muscle tone and spasticity may help to decrease the risk of instrumentation complications, but may also contribute to the progression of scoliosis. While only 3% of patients have neurologic complication, significant equipoise remains regarding whether or not patients should undergo prophylactic detethering procedures to minimize those risks (Sharma et al. in Eur Spine J 22:1230-1249, 2013). Although only 1.8% of complications are classified as cardiac related, they can be among the most devastating (Rumalla et al. in J Neurosurg Spine 25:500-508, 2016). Simply understanding the underlying etiology and the potential risks associated with each condition (i.e., conduction abnormalities in a patient with Rett syndrome or cardiomyopathies patients with muscular dystrophy) can be lifesaving. The following article is a summation of the half day course on neuromuscular scoliosis from the 58th annual SRS annual meeting, summarizing the recommendations from some of the world's experts on medical considerations in surgical treatment of neuromuscular scoliosis.

Krüpple-like factors in cardiomyopathy: emerging player and therapeutic opportunities

Cardiomyopathy, a heterogeneous pathological condition characterized by changes in cardiac structure or function, represents a significant risk factor for the prevalence and mortality of cardiovascular disease (CVD). Research conducted over the years has led to the modification of definition and classification of cardiomyopathy. Herein, we reviewed seven of the most common types of cardiomyopathies, including Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC), diabetic cardiomyopathy, Dilated Cardiomyopathy (DCM), desmin-associated cardiomyopathy, Hypertrophic Cardiomyopathy (HCM), Ischemic Cardiomyopathy (ICM), and obesity cardiomyopathy, focusing on their definitions, epidemiology, and influencing factors. Cardiomyopathies manifest in various ways ranging from microscopic alterations in cardiomyocytes, to tissue hypoperfusion, cardiac failure, and arrhythmias caused by electrical conduction abnormalities. As pleiotropic Transcription Factors (TFs), the Krüppel-Like Factors (KLFs), a family of zinc finger proteins, are involved in regulating the setting and development of cardiomyopathies, and play critical roles in associated biological processes, including Oxidative Stress (OS), inflammatory reactions, myocardial hypertrophy and fibrosis, and cellular autophagy and apoptosis, particularly in diabetic cardiomyopathy. However, research into KLFs in cardiomyopathy is still in its early stages, and the pathophysiologic mechanisms of some KLF members in various types of cardiomyopathies remain unclear. This article reviews the roles and recent research advances in KLFs, specifically those targeting and regulating several cardiomyopathy-associated processes.

Black Cohosh: An Uncommon Culprit of Bradycardia in Postmenopausal Women

The use of herbal supplements has become increasingly prevalent, with black cohosh (BC) gaining popularity for managing menopausal symptoms. However, reports of adverse effects associated with BC are limited. We present a case of bradycardia linked to prolonged BC ingestion. A 76-year-old postmenopausal woman who has been taking BC for years has had syncopal attacks multiple times during the past years associated with bradycardia with the heart rate dropping to 30 beats/minute with no identifiable cause. Discontinuation of BC resulted in a gradual resolution of bradycardia, highlighting a plausible association. There were no additional pharmacological or invasive interventions required.

Benefit of cardiac resynchronization therapy among older patients: A patient-level meta-analysis

BACKGROUND

Cardiac resynchronization therapy (CRT) reduces heart failure hospitalizations (HFH) and mortality for guideline-indicated patients with heart failure (HF). Most patients with HF are aged ≥70 years but such patients are often under-represented in randomized trials.

METHODS

Patient-level data were combined from 8 randomized trials published 2002-2013 comparing CRT to no CRT (n = 6,369). The effect of CRT was estimated using an adjusted Bayesian survival model. Using age as a categorical (<70 vs ≥70 years) or continuous variable, the interaction between age and CRT on the composite end point of HFH or all-cause mortality or all-cause mortality alone was assessed.

RESULTS

The median age was 67 years with 2436 (38%) being 70+; 1,554 (24%) were women; 2,586 (41%) had nonischemic cardiomyopathy and median QRS duration was 160 ms. Overall, CRT was associated with a delay in time to the composite end point (adjusted hazard ratio [aHR] 0.75, 95% credible interval [CI] 0.66-0.85, P = .002) and all-cause mortality alone (aHR of 0.80, 95% CI 0.69-0.96, P = .017). When age was treated as a categorical variable, there was no interaction between age and the effect of CRT for either end point (P > .1). When age was treated as a continuous variable, older patients appeared to obtain greater benefit with CRT for the composite end point (P for interaction = .027) with a similar but nonsignificant trend for mortality (P for interaction = .35).

CONCLUSION

Reductions in HFH and mortality with CRT are as great or greater in appropriately indicated older patients. Age should not be a limiting factor for the provision of CRT.

Burden of bradycardia and barriers to accessing bradycardia therapy in underserved countries

Bradycardia, a condition characterized by an abnormally slow heart rate, poses significant challenges in terms of diagnosis and treatment. While it is a concern world-wide, low- and middle-income countries (LMICs) face substantial barriers in accessing appropriate bradycardia therapy. This article aims to explore the global aetiology and incidence of bradycardia, compare the prevalence and management of the condition in high-income countries versus LMICs, identify the key reasons behind the disparities in access to bradycardia therapy in LMICs, and emphasize the urgent need to address these disparities to ensure equitable healthcare on a global scale.

Evolution of Pacemakers and Implantable Cardioverter Defibrillators (ICDs) in Cardiology

Pacemakers and implantable cardioverter defibrillators (ICDs) have revolutionized cardiology by providing life-saving interventions for patients with cardiac rhythm disturbances. Pacing the heart is an effective treatment for people suffering from bradycardia caused by sinus node dysfunction or atrioventricular (AV) block, and electronic pacing has saved countless lives since its introduction into clinical practice. AV synchronization is the typical cycle of atrial depolarization and contraction followed by ventricular depolarization and contraction. The continuation of this cycle leads to appropriate ventricular filling and cardiac output. By contrast, the failure of the cycle results in AV asynchrony, which may result in heart failure. Cardiac resynchronization treatment (CRT) involves using customized pacemakers with or without implantable cardioverter defibrillators and tries to resynchronize the failing heart by enhancing myocardial contraction without increasing energy consumption. This review delves into the extensive journey of pacemakers and ICDs in the field of cardiology. It highlights the transformative impact of these devices on patient care and quality of life, emphasizing technological advancements, clinical applications, and prospects. This comprehensive review aims to provide insights into the dynamic landscape of cardiac rhythm management.

Abscess after cardiac pacemaker implantation: A case report

This is a report of one of the most serious complications of the cardiac pacemaker implantation - infection of the implanted system. We present the case, which was misdiagnosed at the beginning and after cardiological consultation it was decided to immediately remove the peacemaker and transfer the patient to the Cardiological Department.

Biventricular versus left ventricular only stimulation: an echocardiographic substudy of the B-LEFT HF trial

BACKGROUND

The noninferiority of left ventricular pacing alone (LVp) compared with biventricular pacing (BIV) has not been yet definitely documented. In this study, we reviewed all the original echocardiographic measures of the Biventricular versus Left Univentricular Pacing with ICD Back-up in Heart Failure Patients (B-LEFT HF) trial in order to investigate mechanisms underlying LV remodelling with both pacing modalities.

METHODS

Patients with New York Heart Association functional class (NYHA) III or IV despite optimal medical therapy, LVEF 35% or less, left ventricular end-diastolic diameter (LVEDD) more than 55 mm, QRS duration at least 130 ms were randomized to BIV or LVp for 6 months. The primary end point was a composite of at least 1 point decrease in NYHA class and at least 5 mm decrease in left ventricular end-systolic diameter (LVESD). An additional end point was a LVp reverse remodelling defined as at least 10% decrease in LVESD. Mitral regurgitation and all echocardiographic measures were reassessed after 6-month follow-up.

RESULTS

One hundred and forty-three patients were enrolled. Seventy-six patients were in the BIV and 67 were in the LVp group. Left ventricular volumes decreased significantly without difference between groups (P = 0.8447). Similarly, left ventricular diameters decreased significantly in both groups with a significant decrease in LVESD with BIV (P < 0.0001), but not with LVp (P = 0.1383). LVEF improved in both groups without difference (P = 0.8072). Mitral regurgitation did not improve either with BIV, or with LVp.

CONCLUSION

The echocardiographic sub-analysis of B-LEFT study showed the substantial equivalence of LVp in favouring left ventricular reverse remodelling as compared with BIV.

Electrically stimulated gene expression under exogenously applied electric fields

Introduction: Electrical stimulation, the application of an electric field to cells and tissues grown in culture to accelerate growth and tight junction formation among endothelial cells, could be impactful in cardiovascular tissue engineering, allotransplantation, and wound healing. Methods: Using Electrical Cell Stimulation And Recording Apparatus (ECSARA), the exploration of the stimulatory influences of electric fields of different magnitude and frequencies on growth and proliferation, trans endothelial electrical resistance (TEER) and gene expression of human endothelia cells (HUVECs) were explored. Results: Within the range of endogenous electrical pulses studied, frequency was found to be more significant (p = 0.05) than voltage in influencing HUVEC gene expression. Localization of Yes Associated Protein (YAP) and expression of CD-144 are shown to be consistent with temporal manifestations of TEER. Discussion: This work introduces the field of electromics, the study of cellular gene expression profiles and their implications under the influence of exogenously applied electric fields. Homology of electrobiology and mechanobiology suggests use of such exogenous cues in tissue and regenerative engineering.

Case report of a large lipoma discovered intraoperatively in a chronically irritated implantable cardioverter-defibrillator pocket

Background

The implantation of cardiac implantable electronic devices is a globally established therapy to treat cardiac arrhythmias with low complication rates. Apart from technical problems, however, complications can arise from the implanted material. This can lead to bleeding, infections, or chronic irritation of the generator pocket, resulting in swellings, seromas, perforations, or fistulas. However, the cause of tissue changes is not always clear, and therefore, we would like to report on a rare tissue degeneration diagnosed in a patient.

Case summary

After a history of ventricular fibrillation, a 46-year-old patient received an implantable cardioverter-defibrillator (ICD) for secondary prevention. Six years later, the generator pocket swelled without evidence of infection. With the suspected diagnosis of a chronically irritated pocket, the device was then surgically relocated. After a 2-year symptom-free period, the patient presented again with a severely swollen but only slightly painful device pocket. Once again, there were no signs of infection, and so the pocket was revised again, assuming a chronic irritant effusion. Intraoperatively, a lipomatous structure (12 × 6 × 3 cm) emerged from the subpectoral ICD pocket. After its complete removal, the histopathological examination revealed a lipoma. A bacterial genesis could be ruled out by microbiological samples, and the wound healed cosmetically well and without further discomfort.

Conclusion

This case shows that the reason of chronically irritated generator pockets, in addition to the usually known tissue changes, can also be tumours. Therefore, resected tissue should be examined histopathologically and, if indicated, specific therapy initiated.

Impact of Comorbidity Burden on Cardiac Implantable Electronic Devices Outcomes

Background:

There is limited data on the impact of comorbidity burden on clinical outcomes of patients undergoing cardiac implantable electronic devices (CIED) implantation.

Objectives:

Our aim was to assess trends in CIED implantations and explore the relationship between comorbidity burden and outcomes in patients undergoing de novo implantations.

Methods:

Using the National Inpatient Sample database from 2000 to 2014, we identified adults ⩾18 years undergoing de novo CIED procedures. Comorbidity burden was assessed by Charlson comorbidity Index (CCI), and patients were classified into 4 categories based on their CCI scores (CCI = 0, CCI = 1, CCI = 2, CCI ⩾3). Annual implantation trends were evaluated. Logistic regression was conducted to measure the association between categorized comorbidity burden and outcomes.

Results:

A total of 3 103 796 de-novo CIED discharge records were identified from the NIS database. About 22.4% had a CCI score of 0, 28.2% had a CCI score of 1, 22% had a CCI score of 2, and 27.4 % had a CCI score ⩾3. Annual de-novo CIED implantations peaked in 2006 and declined steadily from 2010 to 2014. Compared to CCI 0, CCI ⩾3 was independently associated with increased odds of in-hospital mortality, bleeding, pericardial, and cardiac complications (all P < .05). Length of stay and hospital charges increased with increasing comorbidity burden.

Conclusions:

CCI is a significant predictor of adverse outcomes after CIED implantation. Therefore, comorbidity burden needs to be considered in the decision-making process for CIED implant candidates.

Systemic immune-inflammation index as a tool for predicting the need for a permanent pacemaker in patients with drug-induced atrioventricular block

BACKGROUND

Drug-induced atrioventricular block (AVB) is generally considered reversible and does not require a permanent pacemaker implantation (PPM). However, some studies have demonstrated a failure of AVB cessation even when the inducing agent has been discontinued. This study has investigated the use of systemic immune-inflammation index (SII) to predict irreversible drug-induced AVB after drug discontinuation.

METHOD

Files of patients with high-degree AVB that required a temporary pacemaker (TPM) were retrospectively analyzed. Sixty-three patients in which AVB was drug-induced were included in the study. The patients were divided into the following two groups: (1) those whose AVB reversed after discontinuation of the related drug, and (2) those in which AVB did not reverse.

RESULTS

AVB reversed in 24 patients (38%) after the inducing agent was discontinued while in the remaining 39 patients (62%) PPM was required. The most common drugs to induce AVB were beta-blockers (n = 46, 73%). Follow-up time with TPM was significantly longer in the irreversible group (2.91 ± 1.05 days vs. 4.94 ± 2.15 days, p < .001). Multivariate logistic regression analysis showed that SII (odds ratio [OR] = 1.002; 95% confidence interval [CI] = 1.000-1.003; p = .01) was an independent predictor of the requirement for a PPM. An SII > 752.05 was found to be a predictor of irreversible AVB requiring PPM with a sensitivity of 64% and specificity of 75% (receiving-operating characteristics [ROC] area under the ROC curve [AUC]: 0.704, 95% CI = 0.570-0.838, p = .007).

CONCLUSION

Approximately 2/3 of drug-induced high-degree AVBs are irreversible. SII is an easily available and cheap inflammatory biomarker that can be used to predict irreversible AVB.

Perioperative Cardiac Risk Reduction in Noncardiac Surgery

Major adverse cardiovascular events are a significant source of morbidity and mortality in the perioperative setting, estimated to occur in approximately 5% of patients undergoing nonemergent noncardiac surgery. To minimize the incidence and impact of these events, careful attention must be paid to preoperative cardiovascular assessment to identify patients at high risk of cardiovascular complications. Once identified, cardiovascular risk reduction is achieved through optimization of medical conditions, appropriate management of medication, and careful monitoring to allow for early identification of-and intervention for-any new conditions that would increase the risk of adverse cardiovascular outcomes. The major cardiovascular and anesthesiology societies in the United States, Europe, and Canada have published guidelines for perioperative management of patients undergoing noncardiac surgery. However, since publication of these guidelines, there has been a practice-changing evolution in the medical literature. In this review, we attempt to reconcile the recommendations made in these 3 comprehensive guidelines, while updating recommendations, based on new evidence, when available.

Remote Monitoring of Permanent Pacemakers and Implantable Cardioverter Defibrillators

Remote monitoring of permanent pacemakers and implantable cardiac defibrillators has undergone considerable advances over the past several decades. Advancement of technology has created the ability for remote monitoring of implantable cardiac devices; a device can monitor its own function, record arrhythmias, and transmit data to health care providers without frequent in-office checks, shown to be as safe as in-office interrogation. Remote monitoring allows earlier detection of clinically actionable events, reduces incidence of inappropriate shocks, and allows earlier detection of atrial fibrillation. App-based remote monitoring provides patients with rapid access to their cardiac data, which may improve compliance with remote monitoring.

Exercise tolerance and quality of life in patients with known or suspected coronary artery disease

BACKGROUND

Coronary artery disease (CAD) is known to impact on patients' physical and mental health. The relationship between performance on treadmill exercise tolerance test (ETT) and health-related quality of life (HRQL)has never been specifically investigated in the setting of CAD.

METHODS

Consecutive patients undergoing an ETT with the Bruce protocol during a diagnostic workup for CAD (n = 1,631, age 55 ± 12 years) were evaluated. Exercise-related indices were recorded. Detailed information on cardiovascular risk factors and past medical history were obtained. HRQLwas assessed with the use of the validated 36-Item Short Form Survey (SF-36) questionnaire.

RESULTS

Increasing age and the presence of cardiovascular risk factors and comorbidities correlated with lower scores on the physical and mental health component of SF-36(all P < 0.05). Subjects with arrhythmias during exercise and slow recovery of systolic blood pressure had lower scores on the physical health indices or the Social Role Functioning component (P < 0.05). Achieved target heart rate and good exercise tolerance were independently associated with better scores of the physical and mental health domains of SF-36 and overall HRQLscores (β = 0.05 for target HR and PCS-36, β = 1.86 and β = 1.66 per increasing stage of exercise tolerance and PCS-36 and MCS-36, respectively, P < 0.001 for all associations). Ischemic ECG changes were associated with worse scores on Physical Functioning (β = - 3.2, P = 0.02) and Bodily Pain (β = - 4.55, P = 0.026).

CONCLUSION

ETT parameters are associated with HRQL indices in patients evaluated for possible CAD. Physical conditioning may increase patient well-being and could serve as a complementary target in conjunction with cardiovascular drug therapy.

Impact of Guidelines on the Diffusion of Medical Technology: A Case Study of Cardiac Resynchronization Therapy in the UK

INTRODUCTION

Research on clinical practice guidelines as a determinant of the diffusion of medical technology remains sparse. We aim to evaluate the impact of guidelines on the awareness of medical technology, as a proxy of its use, with the example of cardiac resynchronization therapy (CRT) in the United Kingdom (UK).

METHODS

We measured clinician awareness based on Google searches performed for CRT that corresponded with actual CRT implant numbers provided by the European Heart Rhythm Association (EHRA). We identified the guideline recommendations published by the National Institute of Health and Care Excellence (NICE) within the UK, the European Society of Cardiology (ESC) at the European level, and the American College of Cardiology Foundation/American Heart Association in the United States (US). We specified a dynamic moving average model, with Google searches as the dependent variable and guideline changes as the independent variables.

RESULTS

One guideline change published by NICE in 2007 and two changes released by the US guidelines in 2005 and 2012 were significantly correlated with the Google searches (p = 0.08, p = 0.02, and p = 0.02, respectively). Guideline changes by the ESC had no significant impact. Changes recommending CRT in place of a conventional pacemaker, in patients with atrial fibrillation, and restricting CRT due to contraindication, remained universally uninfluential.

CONCLUSION

The factors associated with a lack of awareness (as a proxy for technology diffusion) in our case study were: a lack of strong clinical evidence that resulted in the moderate strength of a recommendation, a lack of recognition of any externally published recommendation by NICE, and the frequent release of guidelines with minor changes targeting small patient groups. At least in our case, in the absence of NICE guidelines, the US guidelines received more attention than their non-UK European counterparts, even if the former were released after the latter.

Left Cardiac Sympathetic Denervation Monotherapy in Patients With Congenital Long QT Syndrome

Background:

Videoscopic left cardiac sympathetic denervation (LCSD) is an effective antifibrillatory, minimally invasive therapy for patients with potentially life-threatening arrhythmia syndromes like long QT syndrome (LQTS). Although initially used primarily for treatment intensification following documented LQTS-associated breakthrough cardiac events while on beta-blockers, LCSD as 1-time monotherapy for certain patients with LQTS requires further evaluation. We are presenting our early experience with LCSD monotherapy for carefully selected patients with LQTS.

Methods:

Among the 1400 patients evaluated and treated for LQTS, a retrospective review was performed on the 204 patients with LQTS who underwent LCSD at our institution since 2005 to identify the patients where the LCSD served as stand-alone, monotherapy. Clinical data on symptomatic status before diagnosis, clinical, and genetic diagnosis, and breakthrough cardiac events after diagnosis were analyzed to determine efficacy of LCSD monotherapy.

Result:

Overall, 64 of 204 patients (31%) were treated with LCSD alone (37 [58%] female, mean QTc 466±30 ms, 16 [25%] patients were symptomatic before diagnosis with a mean age at diagnosis 17.3±11.8 years, 5 had [8%] ≥1 breakthrough cardiac event after diagnosis, and mean age at LCSD was 21.1±11.4 years). The primary motivation for LCSD monotherapy was an unacceptable quality of life stemming from beta-blocker related side effects (ie, beta-blocker intolerance) in 56/64 patients (88%). The underlying LQTS genotype was LQT1 in 36 (56%) and LQT2 in 20 (31%). There were no significant LCSD-related surgical complications. With a mean follow-up of 2.7±2.4 years so far, only 3 patients have experienced a nonlethal, post-LCSD breakthrough cardiac event in 180 patient-years.

Conclusions:

LCSD may be a safe and effective stand-alone therapy for select patients who do not tolerate beta-blockers. However, LCSD is not curative and patient selection will be critical when potentially considering LCSD as monotherapy.

Delays in Temporary and Permanent Pacemakers: Causes and In-Hospital Outcomes

Background

Temporary pacemakers frequently serve as a bridge to permanent pacemakers, but placement of the latter may be delayed. This study assessed the causes and in-hospital outcomes of patients with delayed placement of permanent pacemakers.

Methods

This retrospective study included all patients admitted to the Emergency Department who underwent temporary transvenous pacing in the Department of Cardiology, Lady Reading Hospital, Peshawar, Pakistan. The duration of hospitalization and the time from temporary to permanent placement were calculated in days. Asystole, infections, cardiac arrest, and death were recorded during the waiting period.

Results

Of the 260 patients who underwent temporary transvenous pacing, 136 (52.3%) were males and 124 (47.7%) were females, with an age range of 46-78 years. Coronary artery disease was prevalent in 34% of the patients. Only 5% of the patients were on arteriovenous (AV) nodal blocking agents, 44% had complete AV block, 22% had sinus node disease, and 14% had slow atrial fibrillation. The cause of high-degree AV block could not be determined in most patients. Most patients with ischemia- and hyperkalemia-induced AV block recovered. AV blocks induced by ischemia and with no known cause were not reversible, with most of these patients receiving permanent pacemakers. Of the 260 patients with high-degree AV block, 165 (63.5%) recovered. The mean waiting time for permanent pacemaker implantation was 8.7 ± 5.4 days. The waiting time was associated with increased infections and adverse hospital course.

Conclusion

A longer waiting period between permanent pacemaker indication and implantation is dangerous, as it is associated with an increased risk of adverse events such as infections, syncope, asystole, malignant arrhythmias, cardiac arrest, and death.

The role of implantable cardioverter-defibrillators and sudden cardiac death prevention: indications, device selection, and outcome

Multiple randomized multicentre clinical trials have established the role of the implantable cardioverter-defibrillator (ICD) as the mainstay in the treatment of ventricular tachyarrhythmias and sudden cardiac death (SCD) prevention. These trials have focused mainly on heart failure patients with advanced left ventricular dysfunction and were mostly conducted two decades ago, whereas a more recent trial has provided conflicting results. Therefore, much remains to be determined on how best to balance the identification of patients at high risk of SCD together with who would benefit most from ICD implantation in a contemporary setting. Implantable cardioverter-defibrillators have also evolved from the simple, defibrillation-only devices implanted surgically to more advanced technologies of multi-chamber devices, with physiologic bradycardic pacing, including cardiac resynchronization therapy, atrial and ventricular therapeutic pacing algorithms, and subcutaneous ICDs. These multiple options necessitate individualized approach to device selection and programming. This review will focus on the current knowledge on selection of patients for ICD treatment, device selection and programming, and future directions of implantable device therapy for SCD prevention.

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Utilization of implantable cardioverter-defibrillators for the prevention of sudden cardiac death in emerging countries: Improve SCA clinical trial

BACKGROUND

Implantable cardioverter-defibrillators (ICDs) are underutilized in Asia, Latin America, Eastern Europe, the Middle East, and Africa. The Improve SCA Study is the largest prospective study to evaluate the benefit of ICD therapy in underrepresented geographies. This analysis reports the primary objective of the study.

OBJECTIVES

The objectives of this study was to determine whether patients with primary prevention (PP) indications with specific risk factors (1.5PP: syncope, nonsustained ventricular tachycardia, premature ventricular contractions >10/h, and low ventricular ejection fraction <25%) are at a similar risk of life-threatening arrhythmias as patients with secondary prevention (SP) indications and to evaluate all-cause mortality rates in 1.5PP patients with and without devices.

METHODS

A total of 3889 patients were included in the analysis to evaluate ventricular tachycardia or fibrillation therapy and mortality rates. Patients were stratified as SP (n = 1193) and patients with PP indications. The PP cohort was divided into 1.5PP patients (n = 1913) and those without any 1.5PP criteria (n = 783). The decision to undergo ICD implantation was left to the patient and/or physician. The Cox proportional hazards model was used to compute hazard ratios.

RESULTS

Patients had predominantly nonischemic cardiomyopathy. The rate of ventricular tachycardia or fibrillation in 1.5PP patients was not equivalent (within 30%) to that in patients with SP indications (hazard ratio 0.47; 95% confidence interval 0.38-0.57) but was higher than that in PP patients without any 1.5PP criteria (hazard ratio 0.67; 95% confidence interval 0.46-0.97) (P = .03). There was a 49% relative risk reduction in all-cause mortality in ICD implanted 1.5PP patients. In addition, the number needed to treat to save 1 life over 3 years was 10.0 in the 1.5PP cohort vs 40.0 in PP patients without any 1.5PP criteria.

CONCLUSION

These data corroborate the mortality benefit of ICD therapy and support extension to a selected PP population from underrepresented geographies.

Significance of automated external defibrillator in identifying lethal ventricular arrhythmias

Automated electrical defibrillator (AED) is critical in saving children who develop unexpected cardiac arrest (CA), but its diagnostic capacity is not fully acknowledged. Retrospective cohort study of patients with aborted sudden cardiac death (SCD) was performed. Twenty-five patients (14 males) aged 1.3 to 17.5 years who presented with CA survived with prompt cardiopulmonary resuscitation. Eighteen patients had no prior cardiac diagnosis. Cardiac arrest occurred in 10 patients with more than moderate exercise, in 7 with light exercise, and in 8 at rest (including one during sleep). Twenty-two patients were resuscitated with AED, all of which were recognized as a shockable cardiac rhythm. Thorough investigations revealed 6 ion channelopathies (4 catecholaminergic polymorphic ventricular tachycardia, one long QT syndrome, and one Brugada syndrome), 5 congenital heart disease (including 2 with coronary artery obstruction), 6 cardiomyopathies, 2 myocarditis, and 2 miscellaneous. Four patients had no identifiable heart disease. In 5 patients, the downloaded AED-recorded rhythm strip delineated the underlying arrhythmias and their responses to electrical shocks. Four patients who presented with generalized seizure at rest were initially managed for seizure disorder until AED recording identified lethal ventricular arrhythmias.Conclusions: AED reliably identifies the underlying lethal ventricular arrhythmias in addition to aborting SCD. What is Known: • Although infrequent in children, sudden cardiac death (SCD) is often an unexpected and tragic event. The etiology is diverse and sometimes remains unknown despite extensive investigations. • Automated external defibrillator (AED) is both therapeutic in aborting SCD and diagnostic in identifying the underlying lethal ventricular arrhythmias. However, the diagnostic aspect of AED is under-acknowledged by most medical providers. What is New: • Four of 25 patients (16%) were initially managed for possible seizure disorders until AED recording identified lethal ventricular arrhythmia. • The AED recording of the lethal arrhythmia during cardiopulmonary resuscitation (CPR) should always be obtained as it plays a crucial role in the decision-making process before ICD implantation. All medical providers should become familiar with downloading cardiac rhythm strips from AED when requested.

Bradyarrhythmia development and permanent pacemaker implantation after cardiac surgery

OBJECTIVE:

Bradyarrhythmia is one of the complications that may develop after cardiac surgery. Only a few studies have previously dealt with this concern, and in our study, we investigated the factors affecting the development of atrioventricular block or sinus node dysfunction and the requirement of permanent pacemaker following cardiac surgery.

METHODS:

A total of 62 patients who developed the atrioventricular (AV) block or sinus node dysfunction and required a permanent pacemaker following cardiac surgery were included in the study. Among these, 31 patients were evaluated prospectively, and the information regarding 31 patients was evaluated retrospectively based on hospital records. Demographic, clinical, and surgical information was recorded. Patients were grouped according to the types of procedures, including the coronary artery bypass graft, valve surgery, congenital heart disease, and combinations of these. Patients were evaluated by standard 12-lead electrocardiogram and transthoracic echocardiography preoperatively. The postoperative development of bradyarrhythmia and requirement of permanent pacemaker were evaluated.

RESULTS:

The mean age of patients with preoperative conduction abnormality and wide QRS was statistically significantly higher than those without these disorders. The odds ratio for preoperative conduction abnormality risk in patients over 70 years of age was found as 4.429 (95% confidence interval, 1.40–13.93). There was no gender-related statistically significant difference in terms of left ventricular ejection fraction, left ventricular dilatation, interventricular septum thickness, the time interval from operation to the development of AV block, concomitant diseases, and complication rates.

CONCLUSION:

Preoperative conduction abnormality and wide QRS in patients over 70 years of age was determined as a risk factor.

Bradyarrhythmias in Repaired Atrioventricular Septal Defects: Single-Center Experience Based on 34 Years of Follow-Up of 522 Patients

Atrioventricular Septal Defect (AVSD) is a rare congenital heart defect (CHD) often associated with genetic syndromes, most commonly Down syndrome (DS). Over the last four decades, surgical repair has increased survival and improved quality of life in these patients. The prevalence of bradyarrhythmias namely, atrioventricular block (AVB) and sinus node dysfunction (SND) in AVSD is partially known. 522 cases with both partial and complete AVSD (38.7% with DS), undergoing intracardiac repair from 1982 to 2016 at our institution, were reviewed from our system database. 38 (7.3%) patients received permanent PM implantation for AVB (early or late) or SND. On one hand, AVB requiring PM was found in 26 (4.98%). This was further subdivided into early-onset 14 (2.6%) and late-onset AVB 12 (2.2%) (median 4 [IQR 1-7] years). On the other hand, 12 (2.3%) experienced late SND requiring PM (median 11 [IQR 3.5-15.2] years). Early and late AVB were independent from the type of AVSD (partial or complete), whereas the late SND was remarkably observed in complete AVSD compared to partial AVSD (p = 0.017). We classified the cohort into two main categories: DS (202, 38.7%) and non-DS (320, 61.3%). At Kaplan-Meier survival analysis, DS was significantly associated with late-onset bradyarrhythmias (p = 0.024). At Cox regression analysis, we identified DS as an independent predictor of PM implantation (HR 2.17). In conclusion, about 7% of repaired AVSD patients need PM implantation during follow-up. There are no differences in early and late AVB occurrence according to the type of AVSD. There is a higher incidence of late SND in repaired complete AVSD, with a later timing onset in patients with associated DS. Moreover, DS seems to be an independent predictor of PM implantation.

An update on cardiac implantable electronic devices for the general physician

Cardiac electronic device implantation is a common and important intervention for patients with tachy-and bradyarrhythmia. An increasing number of patients are receiving more complex devices such as cardiac resynchronisation therapy or devices with a defibrillation function. Over the last 5 years, two new models of cardiac device have emerged, subcutaneous defibrillators and leadless pacemakers. With an ageing population and data demonstrating 2000 per 100,000 of the population aged over 75 years have a cardiac device, it is essential that the general physician remains updated on the common pacemaker indications and available therapies.

Hypertrophic Cardiomyopathy-Past, Present and Future

Hypertrophic cardiomyopathy (HCM) is the most common genetic cardiomyopathy with a prevalence of 1 in 500 in the general population. Since the first pathological case series at post mortem in 1957, we have come a long way in its understanding, diagnosis and management. Here, we will describe the history of our understanding of HCM including the initial disease findings, diagnostic methods and treatment options. We will review the current guidelines for the diagnosis and management of HCM, current gaps in the evidence base and discuss the new and promising developments in this field.

Long-Term Prognosis of Patients with an Implantable Cardioverter-Defibrillator in Korea

PURPOSE

The objective of this study was to elucidate the long-term prognosis of patients with implantable cardioverter-defibrillators (ICDs) in Korea.

MATERIALS AND METHODS

We enrolled 405 patients (age, 57.7±16.7 years; 311 men) who had undergone ICD implantation. The patients were divided into three groups: heart failure (HF) and ICD for primary (group 1, n=118) and secondary prevention (group 2, n=93) and non-HF (group 3, n=194). We compared appropriate and inappropriate ICD therapy delivery among the groups and between high- (heart rate ≥200 /min) and low-rate (<200 /min) ICD therapy zones.

RESULTS

During the follow-up period (58.9±49.8 months), the annual appropriate ICD therapy rate was higher in group 2 (10.4%) than in groups 1 and 3 (6.1% and 5.9%, respectively, p<0.001). There were no significant differences in annual inappropriate ICD therapy rate among the three groups. In group 1, the annual appropriate ICD therapy rate was significantly lower in patients with a high-rate versus a low-rate therapy zone (4.5% and 9.6%, respectively, p=0.026). In group 3, the annual inappropriate ICD therapy rate was significantly lower in patients with a high-rate versus a low-rate therapy zone (3.1% and 4.0%, respectively, p=0.048).

CONCLUSION

Appropriate ICD therapy rates are not low in Korean patients with ICD, relative to prior large-scale studies in Western countries. Appropriate and inappropriate ICD therapy could be reduced by a high-rate therapy zone in patients with HF and ICD for primary prevention, as well as non-HF patients, respectively.

Prediction of Both Electrical and Mechanical Reverse Remodeling on Acute Electrocardiogram Changes After Cardiac Resynchronization Therapy

BACKGROUND

The development of both electrical reverse remodeling and mechanical reverse remodeling (ERR+MRR) after cardiac resynchronization therapy (CRT) implantation could reduce the incidence of lethal arrhythmia, hence the prediction of ERR+MRR is clinically important.Methods and Results:Eighty-three patients (54 male; 67±12 years old) with CRT >6 months were enrolled. ERR was defined as baseline intrinsic QRS duration (iQRSd) shortening ≥10 ms in lead II on ECG after CRT, and MRR as improvement in LVEF ≥25% on echocardiography after CRT. Acute ECG changes were measured by comparing the pre-implant and immediate post-implant ECG. Ventricular arrhythmia episodes, including ventricular tachycardia and ventricular fibrillation, detected by the implanted device were recorded. Patients were classified as ERR only (n=12), MRR only (n=23), ERR+MRR (n=26), or non-responder (ERR- & MRR-, n=22). On multivariate regression analysis, difference between baseline intrinsic QRS and paced QRS duration (∆QRSd) >35 ms was a significant predictor of ERR+MRR (sensitivity, 68%; specificity, 64%; AUC, 0.7; P=0.003), and paced QTc >443 ms was a negative predictor of ERR+MRR (sensitivity, 78%; specificity, 60%; AUC, 0.7; P=0.002). On Cox proportional hazard modeling, ERR+MRR may reduce risk of ventricular arrhythma around 70% compared with non-responder (HR, 0.29; 95% CI: 0.13-0.65).

CONCLUSIONS

Acute ECG changes after CRT were useful predictors of ERR+MRR. ERR+MRR was also a protective factor for ventricular arrhythmia.

Integration of new technology into clinical practice after FDA approval

Development of new medical technology is a crucial part of the advancement of medicine and our ability to better treat patients and their diseases. This process of development is long and arduous and requires a significant investment of human, financial and material capital. However, technology development can be rewarded richly by its impact on patient outcomes and successful sale of the product. One of the major regulatory hurdles to technology development is the Food and Drug Administration (FDA) approval process, which is necessary before a technology can be marketed and sold in the USA. Many businesses, medical providers and consumers believe that the FDA approval process is the only hurdle prior to use of the technology in day-to-day care. In order for the technology to be adopted into clinical use, reimbursement for both the device as well as the associated work performed by physicians and medical staff must be in place. Work and coverage decisions require Current Procedural Terminology (CPT) code development and Relative Value Scale Update Committee (RUC) valuation determination. Understanding these processes is crucial to the timely availability of new technology to patients and providers. Continued and better partnerships between physicians, industry, regulatory bodies and payers will facilitate bringing technology to market sooner and ensure appropriate utilization.

Decision to Implant a Cardioverter Defibrillator after Myocardial Infarction: The Role of Ejection Fraction v. Other Risk Factor Markers

Background . The Multicenter Automatic Defibrillator Implantation Trial showed that in post—myocardial infarction patients with a left ventricular ejection fraction (EF) ≤ 0.30, an implantable cardioverter defibrillator (ICD) resulted in a 31% relative reduction in the risk of death when compared with a conventional therapy group. Whether further refinement in risk estimation could be achieved with additional clinical testing to qualify patients for primary prevention with ICDs remains problematic. Methods . The authors analyzed Cardiac Arrhythmia Suppression Trial registry data to estimate sensitivity and specificity of EF, ventricular premature frequency, and nonsustained ventricular tachycardia for predicting death. They combined the results with similar data from the literature and used summarizing receiver operating characteristic (meta-ROC) curves to estimate overall operational values for sensitivity and specificity for each clinical test. They estimated aggregate values for prior probability to project risks when tests were used singly and in combination. Results . The authors used arrhythmia markers and heart rate variability to further stratify low-EF patients (prior risk = 20.3%); proportionately, 20.4% were predicted at high risk (> 30%) and 40.5% at low risk (< 10%). When heart rate variability is normal, those at high risk reduced proportionately to 9.2%, and those at low risk increased to 51.6%. Conclusions . The combined use of noninvasive markers for arrhythmia substrate and altered autonomic tone can improve risk stratification in low EF without optimal beta-block therapy, whereas for those with optimal beta-block therapy, markers for arrhythmia substrate alone work. Ancillary use of electrophysiologic stimulation can improve results.

Long-Term Clinical Outcome of Arrhythmogenic Right Ventricular Cardiomyopathy in Individuals With a p.S358L Mutation in TMEM43 Following Implantable Cardioverter Defibrillator Therapy

Background—

We previously showed a survival benefit of the implantable cardioverter defibrillator (ICD) in males with arrhythmogenic right ventricular cardiomyopathy caused by a p.S358L mutation in TMEM43 . We present long-term data (median follow-up 8.5years) after ICD for primary (PP) and secondary prophylaxis in males and females, determine whether ICD discharges for ventricular tachycardia/ventricular fibrillation were equivalent to an aborted death, and assess relevant clinical predictors.

Methods and Results—

We studied 24 multiplex families segregating an autosomal dominant p.S358L mutation in TMEM43 . We compared survival in 148 mutation carriers with an ICD to 148 controls matched for age, sex, disease status, and family. Of 80 male mutation carriers with ICDs (median age at implantation 31 years), 61 (76%) were for PP; of 68 females (median age at implantation 43 years), 66 (97%) were for PP. In males, irrespective of indication, survival was better in the ICD groups compared with control groups (relative risk 9.3 [95% confidence interval 3.3–26] for PP and 9.7 [95% confidence interval 3.2–29.6] for secondary prophylaxis). For PP females, the relative risk was 3.6 (95% confidence interval 1.3–9.5). ICD discharge-free survival for ventricular tachycardia/ventricular fibrillation ≥240 beats per minute was equivalent to the control survival rate. Ectopy (≥1000 premature ventricular complexes/24 hours) was the only independent clinical predictor of ICD discharge in males, and no predictor was identified in females.

Conclusions—

ICD therapy is indicated for PP in postpubertal males and in females ≥30 years with the p.S358L TMEM43 mutation. ICD termination of rapid ventricular tachycardia/ventricular fibrillation can reasonably be considered an aborted death.

Minimizing right ventricular pacing in pacemaker patients with intact and compromised atrioventricular conduction : Results from the EVITA Trial

INTRODUCTION

Unnecessary ventricular pacing is associated with increased morbidity and mortality. Over the years different algorithms have been developed to reduce right ventricular pacing.

OBJECTIVES

Goal of the present study was to test the efficacy of the ventricular intrinsic preference (VIP) algorithm in patients with atrioventricular intact (AVi) and atrioventricular compromised (AVc) AV-conduction.

METHODS

Evaluation of VIP feature in pacemaker patients (EVITA) was a multicenter, prospective, randomized trial (Trials.gov Identifier: NCT00366158). In total, 389 patients were randomized to AVc group: n = 140/132 VIP OFF/VIP On, AVi group: n = 54/63 VIP OFF/VIP ON). One-month post-implantation AV conduction testing (AVc: PR/AR interval > 210 ms) was performed. Follow-up visits occurred 6 and 12 months after DDD-pacemaker implantation.

RESULTS

In AVi and AVc-patients initiation of the VIP feature significantly reduced incidence of ventricular pacing (AVi: 53 ± 38 vs. 9 ± 21%, p = 0.0001; AVc: 79 ± 31 vs. 28 ± 35%, p = 0.0001). DDD-pacemaker implantation per se significantly reduced incidence of AF in VIP ON (AVi 27 vs. 0%, p < 0.0001; AVc 29 vs. 3%, p < 0.0001) and VIP OFF patients (AVi 43 vs. 4%, p < 0.0001; AVc 33 vs. 3, p < 0.0001), without significant differences between VIP ON and OFF groups (p > 0.05). In the AVc group activation of VIP significantly reduced incidence of adverse events (AE). All-cause mortality was not significantly different in VIP ON (n = 5) and VIP OFF (n = 4, p > 0.05) patients.

CONCLUSION

AV search hysteresis (VIP) markedly reduces ventricular pacing both in patients with normal AV conduction and in patients with prolonged PR interval or intermittent AV block.

Eligibility and utilization of implantable cardioverter-defibrillators in a regional STEMI system

BACKGROUND

Studies have shown mortality benefit for implantable cardioverter-defibrillators (ICDs) in ST-elevation myocardial infarction (STEMI) patients with reduced left ventricular ejection fraction (LVEF), but contemporary eligibility and appropriate utilization of ICDs is unknown.

OBJECTIVE

The purpose of this study was to determine the contemporary eligibility and appropriate utilization of ICDs post-STEMI.

METHODS

Using the prospective Minneapolis Heart Institute regional STEMI registry, LVEF before discharge and at follow-up were stratified into 3 groups: normal (LVEF ≥50%), mildly reduced (LVEF 35%-49%), and severely reduced (LVEF <35%).

RESULTS

From March 2003 to June 2012, 3626 patients were treated. Patients with in-hospital death (n = 187), ICD in place (n = 21), negative cardiac biomarkers (n = 337), and undocumented in-hospital LVEF (n = 9) were excluded, leaving 3072 patients in the final analysis, including 1833 (59.7%) with LVEF ≥50%, 875 (28.5%) with LVEF between 35% and 49%, and 364 (11.8%) with LVEF <35% before hospital discharge. Overall, 1029 patients (33.5%) underwent follow-up echocardiography ≥40 days post-STEMI, including 140 of the 364 patients (38.5%) discharged with LVEF <35%. In total, 73 patients (7.1%) with follow-up echocardiography ≥40 days post-STEMI met criteria for an ICD (68 LVEF ≤30%, 5 LVEF 30%-35%, and New York Heart Association class II or greater). Only 26 of these patients (35.6%) underwent ICD placement within 1 year post-STEMI. Overall, only 10% to 15% of potentially eligible patients had an ICD implemented.

CONCLUSION

Rates of ICD implantation in appropriate STEMI patients after 40 days are low. Strategies are needed to identify and expand access to these high-risk patients.

Improved clinical course of autologous skeletal myoblast sheet (TCD-51073) transplantation when compared to a propensity score-matched cardiac resynchronization therapy population

We recently reported a multi-center, single-arm, phase II study that evaluated the efficacy and safety of autologous skeletal myoblast sheet (TCD-51073) transplantation. The advantage of this procedure over a control group has not yet been analyzed. Seven patients with advanced heart failure due to ischemic etiology (TCD-51073 group, New York Heart Association (NYHA) class III; left ventricular ejection fraction (LVEF) <35 %) refractory to optimal medical and coronary revascularization therapy, received TCD-51073 at 3 study centers between 2012 and 2013 with a 2-year follow-up period. As previously reported, 112 patients received cardiac resynchronization therapy (CRT) with follow-up at the University of Tokyo Hospital between 2007 and 2014. Of them, 21 patients were selected for the control group by propensity score matching. No significant difference in baseline variables between the groups was observed. LVEF and NYHA class improved significantly in the TCD-51073 group during the 6-month study period (p < 0.05). During the 2-year follow-up, 7 patients (33 %) in the CRT group and no patient in the TCD-51073 group died due to cardiac disease or received VAD implantation (p = 0.128 by the log-rank test). In conclusion, transplantation of TCD-51073 is clinically advantageous in facilitating LV reverse remodeling, improving HF symptoms, and preventing cardiac death in patients with ischemic etiology when compared to background-matched patients receiving CRT.

Safety and feasibility of biventricular devices reuse in general and elderly population--a single-center retrospective cohort study

Introduction

Cardiac resynchronization therapy (CRT) is known to have very important beneficial effects on heart failure patients. Unfortunately, biventricular implantable cardiac devices (CRT devices), through which this therapy is implemented, are very expensive and sometimes hard to achieve, especially in underdeveloped/developing economies, making this an important problem of public health. As a possible solution, CRT reuse is of great interest nowadays, but unlike simple devices, data in the literature are scarce about biventricular device reuse.

Aim

To address safety concerns, we aimed to analyze infection burden in the general and elderly population and also early battery depletion and generator malfunction of resterilized biventricular devices compared to new devices.

Methods

A cohort of 261 CRT patients (286 devices), who underwent implantation between 2000 and 2014, was retrospectively analyzed. The study group included 115 patients and 127 resterilized devices, that was divided into a subgroup of 69 elderly patients (≥60 years) and 74 devices and a subgroup of 47 younger patients (<60 years) and 53 devices, and the control group included 146 patients and 159 new devices. The groups were compared using a multivariate logistic regression model.

Results

A number of 12 (4.2%) infectious complications were encountered, five (3.9%) in the study group and seven (4.4%) in the control group (odds ratio, 2.83 [0.59–13.44], P=0.189), one (1.3%) in the elderly and four (7.5%) in the younger subgroup (odds ratio, 3.80 [0.36–40.30], P=0.266), with no statistically significant difference between them. There was only one case of early battery depletion, after 17 months, in one study group patient. No generator malfunction was detected.

Conclusion

Reuse of biventricular cardiac implantable electronics seems feasible and safe in both the general population and the elderly population, and it could be a promising alternative when new devices cannot be obtained in a safe period of time.

Sex differences in congenital heart defects and genetically induced arrhythmias

Sex medicine can be applied to define the effect of male or female sex-associated differences on the prevalence of congenital heart defects (CHDs), on clinical manifestation of the latter, on means of dealing with the defects and facing consequent surgical treatment, as well as on the success of surgery. The widespread use of modern databases has undoubtedly enhanced the possibility of these observations compared to the past, when findings were limited to case series from single cardiology or paediatric heart surgery units. The aim of the present review is to assess all publications present in the literature on sex differences and CHD, placing particular emphasis on both contradictory aspects and less acknowledged issues. Furthermore, a section of the review is devoted to the effect of sex differences on cardiac arrhythmias, particularly the largely genetically predetermined electrophysiological differences observed between men and women.

Prevalence of Left Ventricular Dyssynchrony in Patients with Congenital Atrioventricular Block and Long-Term Pacing: A Three-Dimensional Echocardiographic Study

BACKGROUND

Left ventricular (LV) dysfunction is the major reason for poor outcomes in patients with congenital complete atrioventricular block (CCAVB) and pacemaker. Long-term pacing has been associated with LV mechanical dyssynchrony. However, the relationship of dyssynchrony and LV dysfunction is not clear.

OBJECTIVE

We sought to evaluate the prevalence of LV dyssynchrony by real time three-dimensional echocardiography (RT3DE) in patients with CCAVB and its association with LV dysfunction. In addition, we evaluated the agreement between RT3DE and tissue Doppler imaging (TDI) for detecting LV dyssynchrony.

METHOD

We studied 50 patients [median age 20 years old (5 months to 62 years), 68% women] with CCAVB and pacemaker who underwent complete two-dimensional echocardiography and RT3DE. LV dyssynchrony was considered if the systolic dyssynchrony index (SDI) was ≥ 5%. Intraventricular mechanical delay was defined by TDI when differences in electromechanical activation between LV walls were > 65 msec.

RESULTS

LV systolic dysfunction was present in 16 patients (32%) by two-dimensional and in 20 patients (40%) by RT3DE. There was a good correlation between LV ejection fraction by two-dimensional and RT3DE (r = 0.75; P < 0.001). Fourteen (28%) patients had intraventricular dyssynchrony by TDI, while 12 (24%) had intraventricular dyssynchrony by RT3DE. There was a good agreement between LV dyssynchrony by TDI and RT3DE (Kappa = 0.735; P < 0.001). There was a negative correlation between LV ejection fraction and SDI obtained by RT3DE (r = -0.58; P < 0.001) CONCLUSIONS: In patients with CCAVB and long-term pacing, LV dyssynchrony occurred in one-third of patients and was related to LV dysfunction. There was a good correlation between dyssynchrony obtained by RT3DE and TDI.

Prevention of Infections Associated With Permanent Cardiac Antiarrhythmic Devices by Implementation of a Comprehensive Infection Control Program

Objective:

To implement a comprehensive infection control (IC) program for prevention of cardiac device-associated infections (CDIs).

Design:

Prospective before-after trial with 2 years of follow-up.

Setting:

A tertiary-care, university-affiliated medical center.

Patients:

A consecutive sample of all adults undergoing cardiac device implantation between 1997 and 2002.

Intervention:

An IC program was implemented during late 2001 and included staff education, preoperative modification of patient risk factors, intraoperative control of strict aseptic technique, surgical scrubbing and attire, control of environmental risk factors, optimization of antibiotic prophylaxis, postoperative wound care, and active surveillance. The clinical endpoint was CDI rates.

Results:

Between 1997 and 2000, there were 7 CDIs among 725 procedures (mean annual CDI incidence, 1%). During the first 9 months of 2001, there were 7 CDIs among 167 procedures (4.2%; P = .007): CDIs increased from 7 among 576 to 3 among 124 following pacemaker implantation (P = .39) and from 0 among 149 to 4 among 43 following cardioverter-defibrillator implantation (P = .002). Of the 14 CDIs, 5 involved superficial wounds, 7 involved deep wounds, and 2 involved endocarditis. Following intervention, there were no cases of CDI among 316 procedures during 24 months of follow-up (4.2% reduction; P = .0005).

Conclusions:

We observed a high CDI rate associated with substantial morbidity. IC measures had an impact on CDI. Although the relative weight of each measure in the prevention of CDI remains unknown, our results suggest that implementation of a comprehensive IC program is feasible and efficacious in this setting.

Clinical effectiveness of cardiac resynchronization therapy versus medical therapy alone among patients with heart failure: analysis of the ICD Registry and ADHERE

Supplemental Digital Content is available in the text.

Background—

Cardiac resynchronization therapy with defibrillator (CRT-D) reduces morbidity and mortality among selected patients with heart failure in clinical trials. The effectiveness of this therapy in clinical practice has not been well studied.

Methods and Results—

We compared a cohort of 4471 patients from the National Cardiovascular Data Registry’s Implantable Cardioverter-Defibrillator (ICD) Registry hospitalized primarily for heart failure and who received CRT-D between April 1, 2006, and December 31, 2009, to a historical control cohort of 4888 patients with heart failure without CRT-D from the Acute Decompensated Heart Failure National Registry (ADHERE) hospitalized between January 1, 2002, and March 31, 2006. Both registries were linked with Medicare claims to evaluate longitudinal outcomes. We included patients from the ICD Registry with left ventricular ejection fraction ≤35% and QRS duration ≥120 ms who were admitted for heart failure. We used Cox proportional hazards models to compare outcomes with and without CRT-D after adjustment for important covariates. After multivariable adjustment, CRT-D was associated with lower 3-year risks of death (hazard ratio, 0.52; 95% confidence interval, 0.48–0.56; P<0.001), all-cause readmission (hazard ratio, 0.69; 95% confidence interval, 0.65–0.73; P<0.001), and cardiovascular readmission (hazard ratio, 0.60; 95% confidence interval, 0.56–0.64; P<0.001). The association of CRT-D with mortality did not vary significantly among subgroups defined by age, sex, race, QRS duration, and optimal medical therapy.

Conclusions—

CRT-D was associated with lower risks of mortality, all-cause readmission, and cardiovascular readmission than medical therapy alone among patients with heart failure in community practice.

Prognosis of myocardial infarction with left ventricular dysfunction in the coronary revascularization era.Subanalysis of the Japanese Coronary Artery Disease (JCAD) Study

BACKGROUND

Indications of implantable cardioverter-defibrillator (ICD) for patients with an old myocardial infarction (OMI) and left ventricular dysfunction (LVD) were expanded in Western countries after the results of MADIT II. However, the prognosis of OMI patients with LVD and the merits of prophylactic implantation of ICD, based on evidence in Japan, have not yet been clarified. This subanalysis of the Japanese Coronary Artery Disease (JCAD) Study focused on MADIT II-compatible patients to clarify the prognosis of OMI patients with LVD in Japan.

METHODS AND RESULTS

Consecutive 6,868 OMI patients were prospectively followed up for 3 years or until clinical events occurred. 291 patients had left ventricular ejection fraction (LVEF) ≤30%. Clinical events, congestive heart failure, cardiopulmonary arrest on arrival and vascular events were significantly more frequent in patients with LVEF ≤30% than in those with better LVEF. In the LVEF ≤30% group, cardiopulmonary arrest on arrival comprised 33% of all-cause deaths, and the survival curves at 2 years of the LVEF ≤30% group were almost compatible with those of the MADIT II ICD group.

CONCLUSIONS

In this subanalysis, LVD was less frequent than in Western countries. The annual death rate in JCAD was better than for the MADIT II ICD group. The prophylactic use of ICD seemed to be less effective than in Western countries but still expected to be useful for OMI patients with LVD in Japan.